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Q:
The heating capacity of a water-to-water heat pump is highly dependent on the temperatures of the source and sink fluids. a.
True b.
False
Q:
Which two issues must be examined whenever ground water is considered for use with a water-source heat pump? a.
water quantity and average water pressure b.
water quantity and water quality c.
water quality and water hardness d.
water acidity and average water pressure
Q:
In mild climates where sub-freezing temperatures occur only a few days per year, it is acceptable to operate a self-contained air-to-water heat pump with water flowing through the outdoors. a.
True b.
False
Q:
Air-to-water heat pump system designs can often be adapted for use with water-to-water heat pumps. a.
True b.
False
Q:
A wood gasification boiler is a single-stage device. a.
True b.
False
Q:
In general, the larger the temperature difference between the source media and the load media, the higher the heat pumps COP. a.
True b.
False
Q:
Buffer tank sizing depends on the acceptable temperature rise of buffer tank water during the time the heat pump is off. a.
True b.
False
Q:
The purpose of refractory bricks in a welded-steel wood fired boiler is to protect the steel from high temperatures. a.
True b.
False
Q:
For an air-to-water heat pump, COP generally increases with increasing outdoor temperature. a.
True b.
False Indicate the answer choice that best completes the statement or answers the question.
Q:
Desuperheaters transfer more than 60 percent of the total thermal energy in the hot refrigerant gas leaving the compressor to domestic hot water. a.
True b.
False Indicate the answer choice that best completes the statement or answers the question.
Q:
What is the primary purpose of thermal storage used as a buffer? a.
to provide additional space for thermal expansion of the fluid b.
to match the rate of heat production of the heat pump to the heat delivery rate from the distribution system c.
to allow diurnal operation of the heat pump d.
to prevent short-cycling of the heat pump
Q:
What type of flow allows for better heat transfer between the tube wall and the loop fluid? a.
laminar b.
turbulent c.
smooth d.
stagnant
Q:
Which type of system generally has a higher seasonal average COP when properly designed and installed? a.
air-to-water heat pump b.
geothermal heat pump c.
air-to-water and geothermal heat pumps typically have the same COPs d.
COP does not apply to geothermal heat pumps
Q:
Which factor does NOT generally influence undisturbed soil temperature? a.
depth b.
time of year c.
ground loop orientation (horizontal or vertical) d.
thermal properties of the soil
Q:
What type of analysis determines a single variables effect on overall system performance? a.
variable analysis study b.
performance study c.
parametric study d.
metric study
Q:
What solar performance estimating software was developed in the 1970s? a.
F-CHART b.
F-PERCENT c.
TRANS-SOLAR d.
TRNSYS
Q:
Which freeze protection design can be used on domestic water heating systems? a.
antifreeze-protection only b.
drainback-protection only c.
either antifreeze- or drainback-protection d.
neither antifreeze- or drainback-protection
Q:
Which value is generally the most constant over the year in a residential building? a.
the solar fraction b.
the space heating load c.
the auxiliary heating load d.
the water heating load
Q:
How can maximum siphon height be increased within a closed-loop drainback system? a.
increasing the water temperature b.
decreasing the pressure c.
increasing the pressure d.
increasing water levels
Q:
What units are associated with X and Y, as used in the f-Chart method? a.
Btu/hr/sq. ft b.
Btu/hr/sq. ft/degree F c.
fractional percent, expressed in decimal form d.
no units
Q:
What is the recommended flow velocity for establishing a siphon? a.
1 foot per second b.
2 feet per second c.
3 feet per second d.
5 feet per second
Q:
How does F-CHART software estimate economic values? a.
The user inputs relevant economic data. b.
It uses a large internal database of economic values. c.
It uses a historical model. d.
It does not estimate economic values, only solar fractions.
Q:
Practical solar combisystem designs minimize excess energy gain in summer. a.
True b.
False
Q:
How is solar fraction determined once the values of X and Y are known? a.
a nonlinear equation is applied b.
a linear equation with integer constants is applied c.
from the slope and y-intercept of the collector instantaneous efficiency graph d.
it cannot be determined without using software
Q:
The system of units used for inputs to the F-CHART software is not user-configurable. a.
True b.
False
Q:
What F-CHART result indicates the system is probably oversized? a.
more than one summer month in which the solar fraction is over 100 percent b.
less than one summer month in which the solar fraction is over 100 percent c.
any winter month in which the solar fraction is less than 10 percent d.
a consistent solar fraction over a 12 month period
Q:
F-CHART software contains a large internal database of weather data. a.
True b.
False
Q:
What is the recommended minimum spacing when two outdoor air-to-water heat pumps are installed with their air intake sides facing each other? a.
18 inches b.
2 feet c.
4 feet d.
6 feet
Q:
The thermal efficiency of solar collectors, once calculated, remains constant. a.
True b.
False
Q:
What circulates through the closed loop piping during the vapor compression refrigeration cycle? a.
water b.
antifreeze and water c.
refrigerant d.
air
Q:
According to f-Chart method assumptions, the load heat exchanger is the total of all zoned heat emitters operating simultaneously. a.
True b.
False Indicate the answer choice that best completes the statement or answers the question.
Q:
Air-to-water heat pumps always have an external circulator to support flow through the heat pump. a.
True b.
False
Q:
What is the most typical value of the heat exchanger penalty factor for a drainback-protected system? a.
0 b.
1 c.
2 d.
10
Q:
When referring to heating and cooling capacity, one ton represents the average heat transfer rate associated with melting one ton of ice over a 24-hour period. a.
True b.
False
Q:
How was the f-Chart method developed? a.
by repeated application of the TRNSYS model to a single system design b.
theoretical modeling c.
based on empirical correlations from TRNSYS software results using various system designs d.
based on a set of simplified assumptions
Q:
How can space heating energy use be estimated? a.
by using information on average daily water use per person b.
by consulting a climate reference c.
by applying the degree day method d.
by measuring the outside air temperature and multiplying by the buildings volume
Q:
When using F-CHART software, where is the output information displayed? a.
in the solar fraction window b.
in the thermal output window c.
in the solar performance window d.
at the bottom of each input window
Q:
What is the typical range of inputs for the collector slope angle? a.
plus or minus 10 degrees of the local latitude b.
plus or minus 15 degrees of the local latitude c.
plus or minus 10 degrees of the local longitude d.
plus or minus 15 degrees of the local longitude
Q:
In the equations used to calculate X and Y, what does the quantity HT represent? a.
the height of the water in the thermal storage tank b.
the average pitch of the solar collector c.
the average monthly space heating load d.
total daily solar radiation incident on the plane of the collector
Q:
What is typically used to counteract the mixing effects of a vertical flow jet? a.
heat source stratifier b.
reversing the flow direction c.
internal flow diffuser d.
increasing the inlet flow rate
Q:
What should be installed where a solar water heating system connects to the buildings plumbing? a.
thermostatic mixing valve b.
pressure relief valve c.
globe valve d.
heat exchanger
Q:
What happens if the water velocity reaching the top of the collector array is too low? a.
It will entrain many air bubbles. b.
It will not entrain all the air. c.
The siphon will be maintained. d.
The return piping will fill completely with water.
Q:
What is the base chemical used in most automobile antifreeze solutions? a.
ethylene glycol b.
propylene glycol c.
polypropylene glycol d.
ethanol
Q:
What software measures performance of a solar domestic water heating system? a.
F-FLOW b.
F-CHART c.
F-PERCENT d.
FLOW PERCENT
Q:
Which statement is NOT true of drainback-protected solar combisystem designs? a.
They must have sufficient pitch to allow water to drain back. b.
They have more than one operating mode. c.
They must have make up water systems. d.
Their electrical schematics will vary.
Q:
What is the freeze point temperature in an antifreeze-protected solar thermal system? a.
32F b.
the point at which ice crystals begin to form c.
the point at which all liquid has turned to a solid d.
the point at which the system piping may burst
Q:
What is NOT a typical operating mode for an antifreeze-protected solar combisystem? a.
solar collecting mode b.
water heating mode c.
space heating mode d.
discharge mode
Q:
Solar collector efficiency is higher under higher fluid inlet temperatures. a.
True b.
False
Q:
The use of drainback protection (rather than antifreeze protection) involves a thermal penalty associated with the use of a heat exchanger. a.
True b.
False
Q:
Collector absorber plate temperature can exceed 350 degrees if stagnation occurs on a bright summer afternoon. a.
True b.
False
Q:
Once a siphon is established, it is important to maintain it for the duration of the solar energy collection cycle. a.
True b.
False
Q:
Heat dumps and over-temperature protection are not required on drainback-type solar thermal systems. a.
True b.
False
Q:
The collector temperature sensor should be mounted on the piping outside the collector housing. a.
True b.
False
Q:
Fluid flow through a heat exchanger is not required when a swimming pool is used as a heat dump. a.
True b.
False
Q:
Maximum head loss is generally independent of flow rate. a.
True b.
False
Q:
Under stagnation conditions, fluid in the collector may vaporize. a.
True b.
False Indicate the answer choice that best completes the statement or answers the question.
Q:
Drainback systems can use either unpressurized or pressurized thermal storage tanks. a.
True b.
False Indicate the answer choice that best completes the statement or answers the question.
Q:
What two reasons make domestic water heating a practical application for solar thermal systems? a.
intermittent load; heating starts at low temperatures b.
year-round load; heating starts at low temperatures c.
intermittent load; heating starts at high temperatures d.
year-round load; heating starts at high temperatures
Q:
What could occur if system installers fail to compensate for roof sags? a.
The increased average weight of the system may cause the roof to fail. b.
The drainback system will not operate. c.
The system could have a steeper pitch than required. d.
Low points are created where freezing water may occur.
Q:
What configurations may be used for a solar domestic water heating system? a.
internal heat exchanger only b.
external heat exchanger only c.
either internal or external heat exchanger d.
no separate heat exchanger is required
Q:
Which is a benefit of a closed-loop drainback system? a.
Its components last longer because they must be made of non-corroding materials. b.
It can be connected directly to a space heating distribution system. c.
It can be operated at a slight negative pressure. d.
It does not need to accommodate the thermal expansion of system water.
Q:
When does a solar collector array serve as a heat emitter? a.
when configured solely as a water heating source b.
when the over-pressure relief valve opens c.
when the over-temperature relief valve opens d.
during nocturnal cooling
Q:
What is the most typical function of a sight tube in a drainback system? a.
to determine the proper water level in the tank b.
to determine whether the circulator is functioning at capacity c.
to view the collector temperature sensor d.
to accommodate the increased volume of water as temperatures increase
Q:
What type of piping is used with most solar water heating systems today? a.
copper tubing b.
corrugated stainless steel tubing c.
glass tubing d.
soldered stainless steel tubing
Q:
What is different about the collector circulator for drainback-protected systems as compared with that of antifreeze-protected systems? a.
It only needs a single circulator as opposed to two circulators. b.
It must not allow air bubbles to be entrained in the return piping. c.
It must lift water from the static water level in the tank to the top of the collector array. d.
It must have potential for overcoming increased frictional head loss in the collector piping.
Q:
What would result from increasing the pressure rating of the relief valve? a.
A smaller expansion tank would be required. b.
A larger expansion tank would be required. c.
The size of the expansion tank would not be affected. d.
Boiling in the collector array would be prevented.
Q:
What are the two primary factors in sizing the air space in pressurized drainback systems? a.
the average temperature of the outside air and the pitch of the collector piping b.
the number of circulators and the system pressure c.
the pitch of the collector piping and the system pressure d.
the amount of water that drains back and the increased volume of system water with temperature
Q:
What determines the amount of usable heat from storage? a.
average water temperature in the tank and lowest temperature at which the tank can supply heat to the load b.
water temperature at the top of the tank and tank pressure rating c.
minimum water temperature in the tank and the highest temperature at which the tank can supply heat to the load d.
amount of time between cycles of the heat source
Q:
Which code requirements may vary between locations? a.
use of double-wall heat exchangers and collector array grounding b.
percent of total heat load that may be supplied by solar energy c.
requirement for grounding and pressure-relief valves d.
none, because of the requirement of uniform code requirements
Q:
What results when two identical circulators are installed in series? a.
Twice the head is produced at a given flow rate. b.
Half the head is produced at a given flow rate. c.
The head does not change, but the flow rate is cut in half. d.
Less heat is lost from the system.
Q:
What type of valve is used for thermal storage tanks that need to store either heated water or chilled water based on the season of the year? a.
check valve b.
globe valve c.
4-way valve operated by 2-position motorized actuator d.
2-way valve operated by 4-position motorized actuator
Q:
What is the primary purpose of a thermosiphon cooling loop? a.
to prevent stagnation b.
to prevent freezing c.
to be used as a heat dump d.
to extend the life of piping
Q:
What is the recommended minimum downward pitch for drainback-protected solar collector tubes? a.
inch per foot of horizontal travel b.
inch per foot of horizontal travel c.
inch per foot of horizontal travel d.
1 inch per foot of horizontal travel
Q:
Which configuration allows heat to be transferred to the load as quickly as possible after the heat source turns on? a.
2-pipe buffer tank configuration b.
4-pipe buffer tank configuration c.
6-pipe buffer tank configuration d.
vertical flow jet configuration
Q:
Which statement is true of a domestic hot water plus system? a.
Solar energy is used for all the hot water and space heating load. b.
Solar energy is used for most of the hot water and most of the space heating load. c.
Solar energy is used for most of the hot water and a small portion of the space heating load. d.
Solar energy is used for a small portion of the hot water load and most of the space heating load.
Q:
What is the minimum recommended insulation value for piping and components in a drainback system? a.
R-2 b.
R-3 c.
R-10 d.
R-12
Q:
Thermal expansion is not a design concern with unpressurized thermal storage tanks. a.
True b.
False
Q:
Stratification in a thermal storage tank provides more useful energy than an evenly-mixed tank at the same average temperature. a.
True b.
False
Q:
Tankless water heaters have lower amperage requirements than tank-type electric water heaters. a.
True b.
False
Q:
Thermal storage prevents short cycling of the heat source. a.
True b.
False Indicate the answer choice that best completes the statement or answers the question.